Previously known from Finnish patent publication 114903 is a rock drill machine like the one presented, to whose pulling gear that moves the drill rod forward during rock drilling, a separate force in the opposite direction is also directed when needed. Normally, a push force moves the pulling gear forwards and keeps it at a specified distance from the position corresponding to the hammering point of the drill rod. When the drilling equipment is to be pulled out from the hole, the pulling gear is moved towards the hammering piston, causing a transmission force in the pulling gear. Such a percussion like working is needed when pulling the drilling equipment out of the drill hole, since often the drill tries to wedge into the hole while being removed from the hole.
The disadvantage of the solution according to publication FI-114903 is that for the pulling gear a moving arrangement in both directions is needed. When the movements are done by means of pressure medium, the cylinder, piston and packing solutions become quite complicated. In addition, control valves are necessary for both positioning moves, and during pulling out the drilling equipment hammering pulses are transmitted strongly into the drill frame, since there are no spring elements.